1. Field of the Invention
This invention generally relates to pointing devices, and more particularly, to a pointing device designating coordinate positions in a three-dimensional space of directions of height, width, and depth.
2. Description of the Related Art
A pointing device that physically moves in three-axis directions is demanded for pointing a position in the three-dimensional space of an x-axis direction, a y-axis direction, and a z-axis direction displayed on a display screen. Japanese Patent Application Publication No. 6-59811 (hereinafter referred to as Document 1) disclose a device that detects a movement amount in the z-axis direction, based on a rotational amount of two spheres in the x-axis direction, another rotational amount in the y-axis direction, and a difference in these rotational amounts.
The pointing device that physically moves in three axis directions, however, has a complicated configuration as compared to that of the pointing device that physically moves in two axis directions. There arises a problem in that the device cost is more expensive because of the complicated configuration. Document 1 also describes a mechanism of detecting the movement amount in the z-axis direction with the rotational amount of the two spheres. This also complicates the configuration more.